Not willing to rest on the success of the 550 series of sights, EoTech developed the XPS. This sight is approximately half the length of the 550 series sights because its power source comes not from two AA batteries, but a single CR123A. And it's mounted horizontally instead of along the axis of the sight. This allows for more room on a Picatinny rail to mount a magnification device or night vision (the XPS3 version is night vision compatible).
Since I do not have a night vision device, I opted to T&E the XPS2. The sight operates like its older siblings; the on/off/brightness switches are on the rear of the sight, the vertical and horizontal adjustments are on the right side. All movements and actions are clearly indicated on the sight, making it easy as 1,2,3 to operate and adjust the XPS2.[PAGEBREAK]
You also have your choice of mounts; a thumb screw or Allen screw. I chose the thumb screw because if I have to tighten the sight down, a quarter will do. You can use that same quarter to remove the battery case cover and to make sight adjustments. As you can see, this sight is built so you don't have to use special tools to make adjustments. Like its predecessors, the XPS2 is easy to zero and fast on target.
I was concerned how long the battery would last so I used a very "scientific" test. I turned it on and left it on, and three days later the circle dot was still glowing brightly. I figured 72-plus hours of constant on is longer than the sight will be in service.
After the three-day test, I am still using the original battery; it has been in the XPS2 for nearly a year. My guess is you will need to change the battery once or twice a year. As tough as EoTech's sights are, however, I doubt you will have to ever change the sight; it should last you your career.